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I was driving south on Maine’s coast checking out Down East’s picturesque seaside towns when a bridge appeared through the fog, quite like Oz on the horizon. This was not the covered bridge of a quaint New England town, nor the familiar antiquated railroad bridge. This was a looming modern

The observatory of the Penobscott Narrows Bridge can be reached through the Fort Knox Historic Site.

structure more reminiscent of the Zakim Bridge into Boston. The closer we got the more I wondered at the size and stark beauty of this structure.

As it turns out, my husband and I were heading toward the 2,120-foot long Penobscot Narrows Bridge, and for good reason it conjured the Zakim. This 10-year-old bridge is one of only three of its kind in the world: constructed with a cradle system that carries the strands within the stays from bridge deck to bridge deck. The other two bridges of this kind are the Zakim and the Veterans’ Glass City Skyway in Toledo, Ohio.

Towering 420 feet over the town of Bucksport, the bridge’s public observation tower is also the only public bridge observatory in the country and one of four in the world (the others are in China, Slovakia and Thailand). The tallest of the four, it is reached by the fastest elevator in northern New England and gives you 360-degree views of Maine’s coastline, islands and lots of hills and mountains.

But just as impressive as these views is the far less visible but no less superlative accomplishments flowing below the span. The 109-mile Penobscot River tells the story of America’s environmental tragedies, as well as the equally compelling stories of how health and beauty can be restored to our waterways.

The restoration of the Penobscot involved an unprecedented effort to remove two dams and build a state-of-the-art fish bypass around a third. In addition to the Howland Dam bypass, the Milford Dam has a state-of-the-art fish lift installed as part of the restoration project.

A bypass was created for fish around the Howland Dam.

As a result, hundreds of miles of habitat along the Penobscot and its tributaries have been restored, opening the way for sea-run fish, helping the ecology as well as the communities along the river.

In 1999 when Pennsylvania Power and Light purchased a series of dams in Maine, the company approached the Penobscot Indian Nation and several conservation organizations with the idea of working together to relicense the dams. Four years later the company announced it would remove dams along the lower part of the river while keeping hydropower upriver.

The non-profit Penobscot River Restoration Trust was formed, including the Penobscot Indian Nation and six environmental groups — American Rivers, Atlantic Salmon Federation, Maine Audubon, Natural Resources Council of Maine, The Nature Conservancy and Trout Unlimited, who worked with a variety of state and federal agencies, including EPA, on the restoration project.

The Trust in 2010 purchased the Veazie, Great Works, and Howland dams. The first two were removed and a bypass was created around the Howland Dam in 2015 marking the end of this model restoration program.

Before the 1830s, there were no dams on the Penobscot and Atlantic salmon ran upstream in schools numbering 50,000 or more. Shad and alewives migrated 100 miles upriver. Twenty-pound striped bass and Atlantic sturgeon also swam into the river.

Since the restoration, fish have retraced those routes. The salmon run today is considerably smaller than it had been, but still qualifies as the country’s largest Atlantic salmon run. And the population is likely to grow. As this happens, other wildlife that feeds on migrating fish will also do better.

When the restoration is over, 11 species of sea-run fish will have renewed access to habitat that runs from Maine’s high point on Katahdin down to the bay near the Penobscot Narrows Bridge, though not all the species may make it to Katahdin.

The Penobscot Indians fished for American shad as long as 8,000 years ago and sturgeon 3,000 years ago. The logging, dams, and industry along the river put thousands of years of activity to a stop by the 1950s.

Only a generation ago this river was regarded as one of American’s most endangered. It is now considered one of America’s most significant river-restoration efforts.

As you stand in the observatory, turning to look out in 360 degrees, remember to look down at the Penobscot. Sometimes the biggest changes lurk beneath the surface.

Amy Miller is in the public affairs office of EPA’s New England office.

Editor's Note:
The views expressed here are intended to explain EPA policy. They do not change anyone's rights or obligations. You may share this post. However, please do not change the title or the content, or remove EPA’s identity as the author. If you do make substantive changes, please do not attribute the edited title or content to EPA or the author.

EPA's official web site is www.epa.gov. Some links on this page may redirect users from the EPA website to specific content on a non-EPA, third-party site. In doing so, EPA is directing you only to the specific content referenced at the time of publication, not to any other content that may appear on the same webpage or elsewhere on the third-party site, or be added at a later date.

EPA is providing this link for informational purposes only. EPA cannot attest to the accuracy of non-EPA information provided by any third-party sites or any other linked site. EPA does not endorse any non-government websites, companies, internet applications or any policies or information expressed therein.

My family is always giving me a hard time about the difficulty I seem to have completely disconnecting from work. Not only does my ever-present, e-mail-spewing smartphone mean I can keep in touch with my colleagues from virtually any location and at any time, but my job can be really interesting!

As the director of science communications for EPA’s Office of Research and Development, I get a firsthand look at just about every science story that flows from the Agency’s world class scientists and engineers, as well as from a partnership community uniting EPA researchers and other innovators from across the government, academia, business, and beyond. I get a “sneak peak” at an incredible breadth of stories covering everything from tiny nanoparticles, to children’s environmental health, ecosystems assessment, and global climate change adaptation.

With all that going on, you can understand why I find it hard to unplug. Even so, I made a commitment to do my best on a recent family trip. I traveled clear across the country with my husband to visit our son, who lives in the “other” Washington (Washington State).

There, thousands of miles from the office, surrounded by some of the best rafting opportunities anywhere in the world, I came across something that brought my mind right back to work: dam removal. That’s something that our scientific divers have been blogging about right here on It All Starts with Science.

Dam removal has a special place in my heart as there was a dam removed on the river my son—a rafting guide—works on. In fact, we rafted a portion of the White Salmon that had been previously underwater. The canyon was magnificent and it was awesome to see steelhead trout swimming upstream and jumping up waterfalls that they had previously been unable to reach because of the dam.

So, not only did I get to enjoy a somewhat harrowing raft trip with my family, but I got to share what I do and why I like it with a captive audience. For those of you who didn’t have the opportunity to join us on the raft, check out this morning’s blog from our scientific divers about their latest observations and findings. It answers some of the same questions I had about dam removal and what they are learning.

While I’d love to share more about my family vacation and the glorious Pacific Northwest, I’ve got to get back to work. (Oh goodie!)

About the Author: Elizabeth Blackburn is the Director of Communications for EPA’s Office of Research and Development, and an avid fan of wild and scenic rivers anywhere.

Editor's Note:
The views expressed here are intended to explain EPA policy. They do not change anyone's rights or obligations. You may share this post. However, please do not change the title or the content, or remove EPA’s identity as the author. If you do make substantive changes, please do not attribute the edited title or content to EPA or the author.

EPA's official web site is www.epa.gov. Some links on this page may redirect users from the EPA website to specific content on a non-EPA, third-party site. In doing so, EPA is directing you only to the specific content referenced at the time of publication, not to any other content that may appear on the same webpage or elsewhere on the third-party site, or be added at a later date.

EPA is providing this link for informational purposes only. EPA cannot attest to the accuracy of non-EPA information provided by any third-party sites or any other linked site. EPA does not endorse any non-government websites, companies, internet applications or any policies or information expressed therein.

In this second part of our story (see our earlier blog post), we return to the Elwha to talk more about the techniques involved with the survey.

This USGS-led survey involves counting over 65 species of invertebrates and 23 species of algae—all of which we had to memorize before the survey began. As if that wasn’t enough homework for the dive crews, you have to “sneak” up on your critters to actually count them!

Species like Mya truncata clams can “see” you coming and will retract if they can feel the pressure wave of the diver approaching. Likewise, tubeworms are also underwater detectives with their own early warning sensors for approaching divers. Once Schizobranchia insignis or Eudistylia polymorpha tubeworms retract they look remarkably similar!

In buddy teams, divers go down and count algae (kelp, for example) on one side of the transect, and invertebrates (such as clams) on the other. Our divers must adjust for this “shy” behavior when they reach the bottom and “change things up.” Since each diver must count critters and algae on one side of the transect only, the invertebrate scientist tries to count on the downcurrent side of the transect line. After all, the algae-counting scientist has the benefit of their “prey” not running away from them!

EPA diver Scott Grossman conducts a uniform point count along a straight line "transect" placed on the ocean floor. Photo by Alan Humphrey, USEPA.

In addition to counting all the species within one meter of the transect tape for 30 meters for algae and invertebrates respectively, a separate survey is done called a “uniform point count.” Every ½ meter, the diver puts their finger down along the transect tape and counts only what is beneath it. (Even if the most amazing anemone is an inch away, it doesn’t count!) Statistically, the point count and overall tally of species will give a representative assessment of life in the ocean ecosystem near the Elwha River mouth.

Early survey results included a decrease in algae abundance compared to levels seen before the start of dam removal. The decrease may have been due to light deprivation rather than loss of suitable substrate as there was little obvious accumulation of sand or mud on the seafloor. The divers deployed light sensors at many stations to help to document what sort of change in light penetration was occurring at each site. In addition, it seems that tubeworms are on the increase.

What other changes are there? The study will show the changes for the nearly 100 species of algae and invertebrates, in addition to fish, for the largest dam removal effort in North America to date.

Find out more about the wild survey conditions next week in part three of our story.

About the authors: Sean Sheldrake is part of the Seattle EPA Dive unit and is also a project manager working on the Portland Harbor cleanup in Oregon. He and Alan Humphrey both serve on the EPA diving safety board, responsible for setting EPA diving policy requirements. In addition, they both work to share contaminated water diving expertise with first responders and others. Steve Rubin is an aquatic biologist specializing in algal species with the USGS and a lead scientist on the survey.

Editor's Note:
The views expressed here are intended to explain EPA policy. They do not change anyone's rights or obligations. You may share this post. However, please do not change the title or the content, or remove EPA’s identity as the author. If you do make substantive changes, please do not attribute the edited title or content to EPA or the author.

EPA's official web site is www.epa.gov. Some links on this page may redirect users from the EPA website to specific content on a non-EPA, third-party site. In doing so, EPA is directing you only to the specific content referenced at the time of publication, not to any other content that may appear on the same webpage or elsewhere on the third-party site, or be added at a later date.

EPA is providing this link for informational purposes only. EPA cannot attest to the accuracy of non-EPA information provided by any third-party sites or any other linked site. EPA does not endorse any non-government websites, companies, internet applications or any policies or information expressed therein.

Some of you may have followed our previous blog posts about EPA’s scientific diving program in It’s Our Environment, but we also wanted to share some recent work led by U.S. Geological Survey (USGS) and supported by EPA divers near the mouth of Washington State’s Elwha River here in It All Starts with Science.

Now that removal of the Elwha River dams is well under way, USGS scientists, assisted by divers with the Lower Elwha Klallam Tribe, EPA, and Washington Sea Grant, will continue studying the impacts of removal-related sediment to the Strait of Juan de Fuca.

As the first EPA crew to visit the site this year, we didn’t know what to expect.

What we did know—the removal of the Elwha River dams will affect marine habitats in the Strait of Juan de Fuca, primarily from the flow and deposition of released sediment that had accumulated behind the dams for nearly 100 years. That sediment can affect marine life in many ways, including: burial, reduced aquatic reproduction, shading and light reduction, damage to animal gills and filter feeding structures, and changing how different species behave individually and together with their different tolerances and responses to the sediment.

Diving in on the first day, we found the conditions to be very different from before the dams were in place—last year visibility might be up to 50 feet! Not so this year, with some freshwater layers discharging from the Elwha with maybe 6 inches of visibility.

As we descended through this floating “halocline” of different salinity layers (less dense freshwater will sometimes float over the ocean saltwater until it mixes), it was like a “cloud” over the saltwater below. Visibility improved when we made it through, but it was DARK. Where last year the sun was sometimes visible on the seafloor, this year, we needed lights to see the bottom.

Things have changed. For starters, where there had been algal forests, we found much less growth compared to last year. We and our partners will continue to survey Elwha nearshore undersea communities during and after dam removal. Measuring responses to short and long term changes in deposited and suspended sediments offers an unprecedented opportunity to gain insight relevant to managing these important marine resources, and will help to inform how future dam removal projects can be conducted to minimize impact to downstream plants, insects, fish and animals.

About the authors: Sean Sheldrake and Chad Schulze are part of the Seattle EPA Dive unit. Chad is the lead pesticide enforcement in the Northwest, and Sean is also a project manager working on the Portland Harbor cleanup in Oregon. Steve Rubin is an aquatic biologist specializing in algal species with the USGS and a lead scientist on the survey.

Editor's Note:
The views expressed here are intended to explain EPA policy. They do not change anyone's rights or obligations. You may share this post. However, please do not change the title or the content, or remove EPA’s identity as the author. If you do make substantive changes, please do not attribute the edited title or content to EPA or the author.

EPA's official web site is www.epa.gov. Some links on this page may redirect users from the EPA website to specific content on a non-EPA, third-party site. In doing so, EPA is directing you only to the specific content referenced at the time of publication, not to any other content that may appear on the same webpage or elsewhere on the third-party site, or be added at a later date.

EPA is providing this link for informational purposes only. EPA cannot attest to the accuracy of non-EPA information provided by any third-party sites or any other linked site. EPA does not endorse any non-government websites, companies, internet applications or any policies or information expressed therein.